Combination jackscrew and hydraulic cylinder for machine tools



MaY 23, 1950 TURcfHAN ET AL 2,508,587

M. COMBINATION JACK SCREW AND HYDRAULIC CYLINDER FOR MACHINE TOOLS Filed DeC. 7, 1945 2 Shebs-Sheet l May 23, 1950 M. TURcHAN ET AL 2,508,587

COMBINATION JACK SCREW AND HYDRAULIC CYLINDER FOR MACHINE TOOLS Filed Dec. '7, 1945 2 Sheets-Sheet 2 Patented .May 23, 1950 COMBINATION JAcxscREw AND mmm- LIC cYLmDER Fon MAcnnmg'rooLs Manuel Tnrchan, Dearborn, and Curtis Walker,

Detroit, Mich.

Appucaupnnecember 1, 1945, serial No. 633,560

(ci. ssi- 93) 3Claims.

This invention relates to a combination hyldraulic cylinder and screw jack for a machine tool, and more particularly for the vertically adjustable work table supporting knee thereof.

Heretofore, in providing hydraulic cylinders for the machine knee to effect tracer controlled hydraulic vertical adjustments thereof, it was the custom to position a pair of hydraulic cylinders upon the base of said machine on opposite sides of its conventional manually operable screw jack.

The present invention has for its principal object the incorporating of one tracer controlled cylinder with the screw jack itself as a single unit. It is the object of this invention to provide a hydraulic cylinder controlling vertical feeds of the machine work table supporting knee, with the manual screw jack for said knee being positioned centrally through said cylinder.

These and other objects will be seen from the following specification and claims in conjunction with the appended drawings of which:

Fig.- 1 is a front elevational view of the machin tool showing the combination hydraulic cylinder and jack screw for its work table supporting knee.

Fig, 2 is a fragmentary elevational section of the combination hydraulic cylinder and knee jack.

Fig. 3 is a fragmentary elevational section illustrating a slightly different type of nut and screw connection.

It will be understood that the above drawings illustrate merely one preferable embodiment of the invention, and that other embodiments are contemplated within the scope of the claims hereafter set out.

In the drawings, Figure 1, a machine tool is shown consisting of base II, standard I2 thereon with dovetail I3, and cutter head I4, mounted on said standard, carrying rotary cutting tool I5.

Workpiece and pattern supporting table I6 is mounted on knee I1 and adapted for reciprocal horizontal movements thereon on its dovetail connection I8.

' Knee I1 is adjustably mounted on standard I 2, and slidably supported upon dovetail means I3 thereon. Knee I1 is adapted to manual vertical adjustments by means of rotary crank I3 which turns shaft 20.

Rotation of said shaft is adapted to eil'ect rotation of knee elevating screw 2 I, for effecting vertical adjustment of said knee in the manner hereafter set out.

Hydraulic tracer 22, which is adapted to react to the surface of pattern 3| on table I6 is adjustably mounted on bracket arm 23 carried by machine standard |2.

Hydraulic unit 24 includes a pump for supplying fluid under pressure through iiexible conduit 25 which ioins tracer 22. Exhaust iiuid return conduit 26 likewise interconnects tracer 22 and hydraulic unit 24 for returning fluid to the hydraulic unit sump.

-Hydraulic cylinder 21 mounted on base in the manner hereafter described, has a moveable piston therein controlled by pressure fluid from the tracer. Said fluid is directed through either conduit 28 or 23 depending upon the operation of the fluid control valve within tracer 22, which is responsive to movements of spindle 30 reacting to the surface of pattern 3| on worktable I8. Said tracer and the moveable spindle operated valve therein operates in the manner fully set out in applicants Patent No. 2,386,825, dated October 16, 1945, and entitled Tracer mechanism, for eecting reciprocal vertical feed movements of work table I6 which also carries work piece 32 relative to cutter I5.

Ii pressure iluid is delivered through conduit 28 through the vlower end of cylinder 21, the piston therein is forced upwardly, causing upward movement of knee I1; and the uid in said cylinder above saidy piston is returned to tracer 22 through conduit 23 for exhausting through conduit 28 back to the hydraulic unit 24.

On the other hand, if pressure fluid is applied to cylinder 21 through conduit 28, the piston in said cylinder is lowered causing knee I1 to descend, and exhaust fluid returns to tracer 22 through conduit 28.

Referring to Figure 2, fragmentarily shown manually rotatable shaft 20 has a bevel gear 33 on its inner end which meshes with bevel gearv 34 secured by nut 35 upon the upper end of screw 2|. Knee I1 has a horizontal bridge 38 formed Atherein carrying bushing 31 through which screw 2| is rotatably mounted and journaled, with its annular ledge 2| adapted to operatively engage the bottom of bushing 31.

Hollow piston rod 38, which is adapted to reciprocal vertical movements, has an adapter 38 threadably secured to its upper end. Nut 4l threadably engages jack screw 2|, and is secured to the top of adapter 39 by set screws 4|. Said nut is adapted to engage the bottom of bridge 38 which forms a part of knee I1, whereby elevation of piston rod 38 will effect a corresponding elevation of knee I1. On the other hand, with piston rod 38 stationary, manual rotary movements "of screw 2| relative to nut 40, will result in an elevation or depression of said screw 2| effecting corresponding movements of knee bridge 36 relative to nut 46.

Piston rod 38 within which is mounted screw 2| in spaced relation, slidably projects through the upper cap 42 of cylinder 21 withA a suitable packing gland 43 interposed. Lock nut 44 is threaded within the upper hollow annularly flanged portion 45 of cylinder cap 42 and locked in adjusted position therein by locking screw 46.

Said cap is mounted upon the top of cylinder 21 and secured to an annular flange 21 welded thereon, by cap screws 41 arranged adjacent to the periphery thereof. The lower end of cylinder 21 has a bottom cap 48 welded thereto, which in turn is rmly secured to base I by cap screws 49.

` It will be noted that bottom cap 48 has an upwardly projecting portion 50 with passage 5| communicating at one end with the interior of said cylinder, and with its other end terminating at port 52. Referring to Figure 1, it is seen that conduit 28 from the tracer joins port 52 at the bottom of said cylinder for supplying pressure fluid thereto.

Top cap 42 also has a projecting portion 53 Fig. 2 with passage 54 formed therein communicating with the interior of cylinder 21, with its outer end terminating in port 55. As seen in Figure 1. fluid conduit 29 from tracer 22 is joined to port 55 for supplying pressure fluid to the upper end of said cylinder.

Referring to Figure 2, hollow piston rod 38 extends downwardly into and in space relation to tubular member 56. The latter is welded at its top open end to hollow cylinder cap 48 and extends downwardly into vertical opening 51 in base Il. Tubing 56, being in communication with the interior of cylinder 21, forms an extension thereof providing a receptacle for oil.

Piston 58 welded to hollow piston rod 38, has a packing retainer 59 secured thereto by screws 68. Leather packing rings 6| are positioned between piston 58 and retainer 59 and also between said piston and the inner cylinder wall as well as between said packing ring and said inner cylinder wall. An annular metal backing plate 62 is interposed between the two leather packing rings for maintaining the shape thereof. Bolts 68 act to maintain members 58, 59, 6| and 62 as a single piston unit adapted for reciprocation within cylinder 21 in response to pressure fluid on one side or the other in said cylinder.

It will be noted that suitable split expander rings 63 are employed interposed between piston 58 and its packing 6I, and between retainer 59 and its packing 6|. Referring to Figure 2, it is seen that rotatable jack screw.2| is nested within hollow piston rod 38. In the lowest position of piston 58 resting on bottom cap 48, a spaced relation is defined between the bottom of said piston rod and tubing 56.

With screw 2| turned to its lowest position relative to nut 40, it is seen that the bottom of said screw is spaced from the bottom of hollow rod 38.

From above description, it is seen that conventional manual elevation or depression of knee i1 is eifected by hand crank I9 which produces rotation of jack screw 2| relative to stationary nut 48.

Furthermore, it is seen that tracer tip 38 reacting to the surface of pattern 3| as table I6 is fed transversely, controls the flow of pressure fluid from the tracer out either conduit 28 or 29 4 to effect automatic raising or lowering of knee |1 entirely independent of Jack screw 2|.

Referring to Fig. 3, a slightly different type of connection is shown between screw 2l, its nut 64, and the cylinder piston rod 38. Hollow piston rod 38, which is adapted to reciprocal vertical movements, has a cap nut 65 threaded to its upper end. Said nut has a central opening 66 through which screw 2| extends.

Nut 64 threadably engaging screw 2| extends down into piston rod 38. and is securely retained therein by cap 65. The annularly flange portion 61 of nut 64 rests upon the top end of piston rod 38, while cap 65 bears down upon the top of said nut to firmly retain the same.

Set screw 68 is threaded through cap 65, and

`its inner end frictionally engages the sidewall of flange 61 forming part of nut 64 to retain the latter against rotation. Secondary set screw 69 is also threaded through cap 65 with its inner end frictionally engaging the upper end of piston rod 38 to lock said cap in position thereon.

Piston rod 38 is adapted for vertical reciprocal movement through a central opening in upper cap 45 which is secured to the upper end of hydraulic cylinder 21 in the manner shown in Fig. 2.

Packing ring 10 and top and bottom adapters 1| and 12 are carried within cap 45 and interposed between said cap and piston rod 38. Lock nut 13 is threaded down into cap 45 to adjustably and lockingly engage top adapter 1| to effectively seal said cylinder relative to piston rod 38.

With screw 2| manually turned to its lowest position as shown in Fig. 2 it will be seen that annular ledge 2| is spaced from the bottom of bushing 31. Thus, if piston rod 38 is hydraulically elevated, nut 40 engages knee 36 to eect elevation of said knee. However, in almost any other position of screw 2| above its lowest position it will be seen that annular ledge 2 I will be sufficiently above the top of nut 40 so that said ledge will engage the bottom of bushing 31 to effect vertical movements of knee 36.

This is the normal situation, so that in most cases, as in Fig. 1, it can be said that screw 2| actually engages knee 36 to eiect raising or lowering thereof either manually on rotation of handle I9, or hydraulically on vertical movements of piston rod 38 which supports said screw.

Having described our invention, reference should now be had to the claims which follow for determining the scope thereof.

We claim:

1. A jack comprising a hydraulic cylinder, a reciprocal piston therein, a hollow rod in said cylinder closed at its lower end, joined to and extending from opposite sides of said piston and projecting outwardly from said cylinder, and a manually rotating screw threadedly engaging within said rod and projection therefrom, said cylinder having a hollow extension at its lower end to receive the closed end of said rod when said piston and screw are in their lowest positions.

2. A jack comprising a hydraulic cylinder, a reciprocal piston therein, a hollow rod in said cylinder joined to said piston and projecting therethrough and out from said cylinder, a nut with an elongated cylindrical shank projected down into and carried by said rod, an adapter on said shank and threadedly secured to said rod, set screws extending through said nut and threadedly engaging said adapter adapted to retain said nut relatively to said rod, and a man- 5 ually rotatable screw within said rod threadedly engaging said nut and adapted for movement relatively to said cylinder.

3. A jack comprising a hydraulic cylinder, a

reciprocal piston therein, a hollow rod in said 5 cylinder.

MANUEL TURCHAN CURTIS WALKER.

6 REFERENCES crrED The following references are of record in the iile of this patent:

UNITED STATES PATENTS Number Name Date 1,228,586 Mulvihill June 5, 1917 1,463,654 McNulty July 31, 1923 1,925,652 Bolens Sept. 5, 1933 10 2,352,390 Kirkland June 27, 1944 FOREIGN PA'I'ENTS Number Country Date 464,306 Great Britain Apr. 15, 1937 

